CBFalconer wrote:
Emil Jerabek wrote:
... snip ...
Sorry, should think twice before submitting a bugreport. The story with "file of record end" is more complicated then I wrote.
The test below should pass for any type (which is permissible as a file component-type, of course). It indeed works with, say, "file of Integer", but with the empty record type it fails:
[...]
I have not checked the standards, but is the problem accepting the empty record? It seems like a pointless thing to do, leading to all sorts of problems, such as:
Sure, it is completely pointless, except that it _is_ mandated by the standard. Namely, section 6.4.3.4 (Record-types) of ISO 10206 says:
...
record-type = `record' field-list `end' .
field-list = [ ( fixed-part [ `;' variant-part ] | variant-part ) [ `;' ] ] .
...
A field-list containing neither a fixed-part nor a variant-part shall have no components, shall determine a single value-bearing state bearing a null value, shall be designated empty, and shall denote the totally-undefined initial state.
...
TYPE per = ^emptyrecord; VAR erarray : ARRAY[1..N] OF emptyrecord;
... new(per); erarray[i] := erarray[j]; erarray[i] := per^; per^ := erarray[i]; dispose(per);
Well, what's the problem here? All these assignment statements are simply no-ops.
etc. Accepting that has further problems with the design of the memory allocation mechanism - I have just built one for DJGPP and had to detect a zero size and increment it, otherwise storage needed for free block tracking would have been missing. The ramifications of an empty object go on and on and on and ....
-- Chuck F (cbfalconer@yahoo.com) (cbfalconer@XXXXworldnet.att.net) Available for consulting/temporary embedded and systems. (Remove "XXXX" from reply address. yahoo works unmodified) mailto:uce@ftc.gov (for spambots to harvest)
Emil Jerabek
Emil Jerabek wrote:
CBFalconer wrote:
Sure, it is completely pointless, except that it _is_ mandated by the standard. Namely, section 6.4.3.4 (Record-types) of ISO 10206 says:
TYPE per = ^emptyrecord; VAR erarray : ARRAY[1..N] OF emptyrecord;
... new(per); erarray[i] := erarray[j]; erarray[i] := per^; per^ := erarray[i]; dispose(per);
Well, what's the problem here? All these assignment statements are simply no-ops.
Indeed.
Accepting that has further problems with the design of the memory allocation mechanism - I have just built one for DJGPP and had to detect a zero size and increment it, otherwise storage needed for free block tracking would have been missing. The ramifications of an empty object go on and on and on and ....
Well, GPC's memory management works with size 0 at least. That's not the problem.
Frank
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Emil Jerabek -
Frank Heckenbach